Xylometazoline is a potent, direct-acting sympathomimetic amine used as a topical nasal decongestant. It is a selective alpha-2 adrenergic receptor agonist, causing vasoconstriction of the dilated arterioles in the nasal mucosa, leading to reduced blood flow, decreased edema, and relief of nasal congestion. The 1% w/v concentration is a standard strength for intranasal use in adults and children over 12 years.
Adult: 2-3 drops or 1-2 sprays (approx. 0.1 mL) into each nostril. May be repeated every 8 to 10 hours as needed. Do not exceed 3 applications in 24 hours.
Note: 1. Blow nose gently to clear nostrils. 2. Tilt head slightly back. 3. Insert applicator tip just inside nostril. 4. For sprays: Squeeze bottle quickly and firmly while breathing in gently through the nose. For drops: Instill prescribed number of drops. 5. Avoid touching the dropper/tip to the nostril to prevent contamination. 6. Do not share the bottle. 7. Use for a maximum of 5-7 consecutive days.
Xylometazoline acts as a direct agonist on postsynaptic alpha-2 adrenergic receptors located on vascular smooth muscle within the nasal mucosa. This stimulation activates the G-protein coupled receptor, leading to increased intracellular calcium levels, resulting in smooth muscle contraction (vasoconstriction). This constricts the dilated arterioles and venous sinusoids, reducing blood flow, capillary engorgement, and tissue edema, thereby shrinking the nasal turbinates and opening the nasal airway.
Pregnancy: Category C: Animal reproduction studies have shown an adverse effect on the fetus, but there are no adequate and well-controlled studies in humans. Use only if the potential benefit justifies the potential risk to the fetus. Should be used at the lowest effective dose for the shortest duration.
Driving: Unlikely to affect the ability to drive and use machines when used at recommended doses. Drowsiness has been reported rarely.
| Monoamine Oxidase Inhibitors (MAOIs) e.g., Phenelzine, Tranylcypromine | Risk of severe, potentially fatal hypertensive crisis due to potentiation of sympathomimetic effects. | Contraindicated |
| Tricyclic Antidepressants (TCAs) e.g., Amitriptyline | May potentiate the pressor effects of xylometazoline. | Major |
| Other Sympathomimetic Agents (e.g., Pseudoephedrine, Phenylephrine) | Additive sympathomimetic effects, increasing risk of hypertension, tachycardia, and CNS stimulation. | Moderate |
| Beta-blockers (e.g., Propranolol) | Unopposed alpha-adrenergic stimulation may lead to severe hypertension and bradycardia. | Moderate |
| Methyldopa | May potentiate pressor response. | Moderate |